And what the heck are purple and white potatoes? We have answers.

Sometimes life puts you at a crossroads: Do you buy yams or sweet potatoes? They often look identical, but I've found that "yams" can be as low as 79 cents per pound, while "sweet potatoes" cost $2.49 per pound. So, what's the difference between a sweet potato and a yam? At most grocery stores, absolutely nothing. It's all a facade! "Most of the so-called yams you see in American grocery stores are actually orange-fleshed sweet potatoes," explains Mary-Frances Heck, author of new cookbook Sweet Potatoes (and former BA staffer). The reason for the name mix-up, she explains, is because Louisiana sweet potato growers marketed their orange-fleshed as “yams” to distinguish from other states' produce in the 1930s—and it stuck.

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The skin of a yam (left) looks kind of like tree bark, while a sweet potato (right) is more reddish-brown.

Real yams are entirely different root vegetables that are more like yucca in texture and flavor. They have bumpy, tough brown skin (that looks almost tree trunk-like) with starchy, not sweet flesh. Yams are more easily compared to the texture and flavor of white russet potatoes (with more fiber and complex carbs) and are best boiled and served alongside hearty braised meats. The neutrally-flavored yams are often used in Caribbean or West African cooking, and are difficult to find in the U.S.; sometimes you can pick them up at specialty grocery stores.

To make life even more complicated, there are a handful of varieties of sweet potatoes: orange, white, and purple. We had Heck break down the differences for us.

Orange Sweet Potatoes

Kristin Teig

Sweet potato Cobb salad.

These are the sweet potatoes that you roast for meal prep, use for Thanksgiving sweet potato pie or marshmallow-topped mashed potatoes, and snack on as fries and chips. They're versatile, easy to find, and the varietals within the orange-fleshed potatoes are all "pretty much interchangeable," says Heck. She notes there will be "subtle differences in flavor, sweetness, and moisture" between Beauregard (brown skin, more deeply sweet, grown in Louisiana), Garnet (red skin, more like pumpkin flavor), and Jewel (coppery-orange skin, mildly sweet and earthy, California-grown).

Heck argues that sweet potatoes should be your new vegetarian meat replacement because they "can carry spices in a way that other vegetables can't." Standard white potatoes' flavor would be obliterated by a heavy seasoning from Spanish paprika, black pepper, and garlic, but it works perfectly as a bacon-ish flavor in her Cobb salad recipe (pictured above) or with cumin and coriander for tacos.

White Sweet Potatoes

White sweet potatoes may look like russets, but they're loaded with some of the same fiber and vitamins that orange sweet potatoes have—though not as much beta-carotene. Since they're a little drier in texture, Heck suggests using them for gnocchi so you can control the amount of moisture in the dough. For non-pasta applications, Heck says they go really well with bright, acidic sauces like chimichurri. The texture is more toothsome than mushy when roasted, but if you braise them low and slow, they end up being silky yet still hold their shape.

Purple Sweet Potatoes

Kristin Teig

Sambal-buttered purple sweet potatoes.

Purple sweet potatoes have super amped-up anthocyanins like blueberries, which are great for both color and antioxidants. The North Carolina-grown Stokes varietal are the most popular (with a sweet chestnut flavor), but you can sometimes find Hawaiian Okinawan potatoes with purple-speckled flesh that are best boiled whole. To prevent the color from bleeding out when cooking, Heck suggests roasting, sautéeing, or frying purple sweet potatoes. One of Heck's favorite ways to eat them is topped with sambal butter. You can either make your own sambal paste with chiles, garlic, ginger, lemongrass, lime zest, and salt, or just mix 1 Tsbp. sambal oelek with a stick of butter. As it melts into your potato, all your problems may melt away too.